scholarly journals Mangrove Dieback and Leaf Disease in Sonneratia apetala and Sonneratia caseolaris in Vietnam

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1273 ◽  
Author(s):  
Huong Thi Thuy Nguyen ◽  
Giles E. St. J. Hardy ◽  
Tuat Van Le ◽  
Huy Quoc Nguyen ◽  
Duc Hoang Le ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Fungal Pathogens ◽  
Survival Rates ◽  
Tree Decline ◽  
Mangrove Restoration ◽  
Sonneratia Caseolaris ◽  
Leaf Spots ◽  
Black Leaf Spot ◽  
Stem Lesions

Even though survival rates for mangrove restoration in Vietnam have often been low, there is no information on fungal pathogens associated with mangrove decline in Vietnam. Therefore, this research was undertaken to assess the overall health of mangrove afforestation in Thanh Hoa Province and fungal pathogens associated with tree decline. From a survey of 4800 Sonneratia trees, the incidence of disorders was in the order of pink leaf spot > shoot dieback > black leaf spot for S. caseolaris and black leaf spot > shoot dieback > pink leaf spot for S. apetala. Approximately 12% of S. caseolaris trees had both pink leaf spot and shoot dieback, while only 2% of S. apetala trees had black leaf spot and shoot dieback. Stem and leaf samples were taken from symptomatic trees and fungi were cultured in vitro. From ITS4 and ITS5 analysis, four main fungal genera causing leaf spots and shoot dieback on the two Sonneratia species were identified. The most frequently isolated fungal taxa were Curvularia aff. tsudae (from black leaf spot),Neopestalotiopsis sp.1 (from stem dieback), Pestalotiopsis sp.1 (from pink leaf spot), and Pestalotiopsis sp.4a (from black leaf spot). The pathogenicity of the four isolates was assessed by under-bark inoculation of S. apetala and S. caseolaris seedlings in a nursery in Thai Binh Province. All isolates caused stem lesions, and Neopestalotiopsis sp.1 was the most pathogenic. Thus, investigation of fungal pathogens and their impact on mangrove health should be extended to other afforestation projects in the region, and options for disease management need to be developed for mangrove nurseries.

scholarly journals Antibiotic sensitivity in correlation to the origin of secondary peritonitis: a single center analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rainer Grotelüschen ◽  
Lena M. Heidelmann ◽  
Marc Lütgehetmann ◽  
Nathaniel Melling ◽  
Matthias Reeh ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Medical Center ◽  
Survival Rates ◽  
Antibiotic Sensitivity ◽  
Secondary Peritonitis ◽  
Source Control ◽  
Emergency Laparotomy ◽  
Strong Impact ◽  
In Vitro Susceptibility

Abstract Despite improvements in diagnosis, intensive-care medicine and surgical technique, the mortality of patients with secondary peritonitis is still high. Early and aggressive empiric antibiotic treatment has strong impact on the outcome. This retrospective study investigates bacterial and fungal pathogens and their antibiotic sensitivity in patients with secondary peritonitis. All patients that underwent emergency laparotomy due to secondary peritonitis at the Department of Surgery, University Medical Center Hamburg-Eppendorf between 2005 and 2015 were reviewed and overall 414 patients were included. We correlated the intra-abdominal localization of the organ perforation with intraoperative microbiological findings and corresponding sensitivities to relevant antibiotics. Overall, the most common findings were Escherichia coli (39%) and other Enterobacterica (24%). Depending on the location of the perforation, Cefuroxime/Metronidazole and Cefutaxime/Metronidazole were effective (based on in vitro susceptibility testing) in only 55–73% of the patients, while Meropenem/Vancomycin was able to control the peritonitis in more than 98% of the patients; independent of the location. Besides early source control, appropriate empiric treatment plays a pivotal role in treatment of secondary peritonitis. We are able to show that the frequently used combinations of second or third generation Cephalosporins with Metronidazole are not always sufficient, which is due to the biological resistance of the bacteria. Further clinical studies are needed to determine whether calculated use of broad-spectrum antibiotics with a sensitivity rate > 99%, such as Carbapenem plus Vancomycin, can improve overall survival rates in critically ill patients with secondary peritonitis.

Apical chlorosis and leaf spot of Tagetes spp. caused by Pseudomonas tagetis Hellmers

1978 ◽  
Vol 29 (4) ◽  
pp. 831 ◽  
Author(s):  
D Trimboli ◽  
PC Fahy ◽  
KF Baker
Keyword(s):  
Leaf Spot ◽  
Zinnia Elegans ◽  
Tagetes Erecta ◽  
Diverse Range ◽  
Biochemical Characteristics ◽  
Leaf Spots ◽  
Spray Inoculation

An undescribed apical chlorosis caused severe losses in seedlings of Tagetes erecta and T. patula types in Sydney, Brisbane and Melbourne in 1976. Bacterial leaf spots without chlorotic haloes invariably accompanied the disease. The same bacterium was isolated from leaf lesions and chlorotic tissue and produced leaf spots and chlorosis on marigold, zinnia and sunflower with spray inoculation. Leaf spots did not develop on T. signata. Apical chlorosis developed on a diverse range of plants following wound inoculation. The pathogen was shown to be seed-borne. The pathogen was identified as Pseudomonas tagetis, cultural and biochemical characteristics described, and a neotype culture proposed. An exotoxin was produced in vitro which caused apical chlorosis in Zinnia elegans and T. patula.

scholarly journals Determining the Sources of Primary and Secondary Inoculum and Seasonal Inoculum Dynamics of Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Plant Disease ◽  
2019 ◽  
Vol 103 (5) ◽  
pp. 951-958
Author(s):  
Shan Lin ◽  
Francesca Peduto Hand
Keyword(s):  
Leaf Spot ◽  
Fungal Pathogens ◽  
Disease Incidence ◽  
Fruit Rot ◽  
Plant Production ◽  
Mature Fruit ◽  
Average Temperature ◽  
Leaf Spots ◽  
Maximum Minimum

Fruit rot of deciduous holly, caused by species of the genera Alternaria, Colletotrichum, Diaporthe, and Epicoccum, is affecting plant production in Midwestern and Eastern U.S. nurseries. To determine the sources of inoculum, dormant twigs and mummified fruit were collected, and leaf spot development was monitored throughout the season from three Ohio nurseries over two consecutive years. Mummified fruit was the main source of primary inoculum for species of Alternaria and Epicoccum, whereas mummified fruit and bark were equally important for species of Colletotrichum and Diaporthe. Brown, irregular leaf spots developed in the summer, and disease incidence and severity increased along with leaf and fruit development. Coalesced leaf spots eventually resulted in early plant defoliation. When tested for their pathogenicity on fruit, leaf spot isolates were able to infect wounded mature fruit and induce rot symptoms, which indicated that leaf spots could serve as a source of secondary inoculum for fruit infections. In addition, spore traps were used to monitor seasonal inoculum abundance in the nurseries. Fruit rot pathogens were captured by the spore traps throughout the season, with peak dissemination occurring during flowering. In this study, we also attempted to understand the role of environmental factors on leaf spot development. Although leaf spot incidence and severity were negatively correlated to mean maximum, minimum and average temperature, a decrease in temperature also coincided with leaf senescence. The role of temperature on leaf spot development should be further studied to fully interpret these results.

scholarly journals In vitro antifungal activity of endophytic bacteria isolated from date palm (Phoenix doctylifera L.) against fungal pathogens causing leaf spot of date palm

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
H. H. Al-Nadabi ◽  
N. S. Al-Buraiki ◽  
A. A. Al-Nabhani ◽  
S. N. Maharachchikumbura ◽  
R. Velazhahan ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Endophytic Bacteria ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Date Palm ◽  
Dual Culture ◽  
Bacterial Endophytes ◽  
Bacterial Strains ◽  
Culture Filtrates

Abstract Background Date palm ((Phoenix doctylifera L.) suffers from several fungal diseases. The endophytic microorganisms present in higher plants generally offer protection to their host plants against invading phytopathogenic fungi and bacteria. In the present study, endophytic bacteria associated with date palm leaves were isolated and their in vitro antagonistic potential against fungal pathogens causing leaf spots in date palm was demonstrated. Results Endophytic bacteria were isolated from date palm leaves of 3 different cultivars viz., Nighal, Khalas and Khinaizi and evaluated for their inhibitory activity against leaf spot pathogens of date palm viz., Fusarium solani, Alternaria sp., Nigrospora sp., Thieloviopsis sp., Curvularia subpapendrofii and Tilletiopsis minor using an in vitro dual culture assay. Of the 24 endophytic bacterial strains tested, the endophytes designated B1, B7, B8 and B9 obtained from cv. Nighal showed inhibitory activities (more than 55% mycelial growth inhibition) against F. solani and Alternaria sp. None of the bacterial endophytes inhibited the growth of other fungal pathogens tested. These antagonistic bacterial strains were identified as Pantoea septica on the basis of 16S rRNA gene sequence analysis. The hyphae of F. solani and Alternaria sp. exhibited morphological abnormalities such as shrinkage and disintegration when grown in the presence of antagonistic bacterial endophytes. The cell-free culture filtrates of the bacterial endophytes caused inhibition of mycelial growth and induced leakage of electrolytes from the mycelia of F. solani and Alternaria sp. This is the first study that describes inhibition of the date palm pathogens F. solani and Alternaria sp. by P. septica. Conclusion Endophytic Pantoea septica strains isolated from date palm leaves inhibited the mycelial growth of F. solani and Alternaria sp. and induced morphological changes in their mycelia. The culture filtrates of these bacterial strains also inhibited the mycelial growth and caused leakage of electrolytes from the mycelia of F. solani and Alternaria sp. These promising bacterial strains can be exploited as biocontrol agents to control F. solani and Alternaria sp.-induced leaf spot diseases of date palm.

scholarly journals Pestalotiopsis desseminata PADA JAMBU MENTE BIOLOGI DAN INTERAKSINYA DENGAN Helopeltis antonii

2020 ◽  
Vol 6 (3) ◽  
pp. 66
Author(s):  
ESTHER M. ADHI ◽  
SUPRIADI SUPRIADI ◽  
S. RAHAYUNINGSIH ◽  
D. KILIN ◽  
NURI KARYANI
Keyword(s):  
Leaf Spot ◽  
Mycelial Growth ◽  
Agar Medium ◽  
Fungal Growth ◽  
Pathogenicity Test ◽  
Leaf Spots ◽  
Fungal Biology ◽  
Mycelia Growth ◽  
Medicinal Crops

<p><strong>Pestalotiopsis desseminata on cashew: its biology and interaction with Helopeltis antonii</strong></p><p>Pestalotiopsis desseminata is one of pathogens causing leaf spots. die-back of shoots and inflorescence of cashew plant. It is assumed there is an interaction between the attack of Helopeltis antonii and the fungus in Ihe ield so that the damage becomes more devastating. The objectives of (his research were to investigate several aspects of fungal biology (pathogenicity, mycelial growth, acervuli production, sensitivity to fungicides) and its interaction with //. antonii. The esearch was carried out from April 1999 to March 2000 at the laboratory and green house of Pest and Disease Department Research Institute for Spice and Medicinal Crops, Bogor. /' desseminata was diectly isolated from cashew leaves. Pathogenicity test of P. desseminata isolate was conducted on cashew seedlings. The fungal growth and fungicide effects were carried out in vitro on agar medium. The interaction between P. desseminata and H. antonii was examined by inoculating the fungus and insect, either individually or in combination, on cashew seedlings. The results showed that P. desseminata isolate fomis black spherical acervuli containing oblongs conidia with 5 cells, and the outermost cell has 3 flagellate. Acervuli could only be produced on the cultue illuminated continuously by 600 lux translucent lamp. Pathogenicity test of several isolates of /' desseminata on cashew seedlings caused spherical leaf spot symptom, individually or coalesced as bigger leaf spots. In vitro fungal mycelia growth could be suppressed by several fungicides, including bcnomyl 50% (I ppm) and Uiiopanate-mcthyl 70% (10 ppm) Combining inoculation between P. desseminata and //. antonii resulted in moe severe (devastating) die-back compared with individually inoculated.</p>

scholarly journals Fungi associated with leaves of Sonneratia apetala Buch. Ham and Sonneratia caseolaris (L.) Engler from Rangabali coastal zone of Bangladesh

2018 ◽  
Vol 27 (2) ◽  
pp. 155-162
Author(s):  
Shamim Shamsi ◽  
Sarowar Hosen ◽  
Ashfaque Ahmed
Keyword(s):  
Aspergillus Fumigatus ◽  
Leaf Spot ◽  
Black Spot ◽  
Colletotrichum Lindemuthianum ◽  
Sonneratia Apetala ◽  
Sonneratia Caseolaris ◽  
Phoma Betae ◽  
Black Leaf Spot ◽  
Planting Method ◽  
First Time

A total of six species and one genus of fungi associated with black leaf spot of Sonneratia apetala Buch. Ham (Kewra); and anthracnose and small leaf spot of S. caseolaris (L.) Engler (Choila) were isolated following “Tissue planting” method. The fungi associated with black spot of S. apetala were Aspergillus fumigatus Fresenius, Colletotrichum lindemuthianum (Sacc. & Magn.) Br. & Cav., Pestalotiopsis guepinii (Desm.) Stey. and Phoma betae Frank. Anthracnose of S. caseolaris showed the association of A. fumigatus and P. guepinii. The fungi associated with leaf spot of S. caseolaris were Curvularia fallax Boedijn, Fusarium Link, Penicillium digitatum (Pers.) Sacc. and P. betae. Frequency percentage of association of P. guepinii was highest (74.10) in black spot of S. apetala whereas the same fungus showed highest frequency percentage (85.70) in case of anthracnose of S. caseolaris. Phoma betae showed highest frequency percentage (60.00) in leaf spot of S. caseolaris. Phoma betae is first time recorded from Bangladesh. Dhaka Univ. J. Biol. Sci. 27(2): 155-162, 2018 (July)

Septoria chrysanthemella. [Descriptions of Fungi and Bacteria].

1967 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Geographical Distribution ◽  
Leaf Spot ◽  
Tagetes Patula ◽  
Leaf Spots ◽  
Chrysanthemum Indicum ◽  
Previous Season ◽  
Brown Leaf Spot ◽  
Water Splash ◽  
Brown Leaf ◽  
Black Leaf Spot

Abstract A description is provided for Septoria chrysanthemella. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Chrysanthemum indicum, C. japonicum, C. morifolium, C. parthenium. Also by inoculation on C. azaleanum, C. koreanum, C. leueanthemum, C. segetum, C. roseum, Tagetes patula, Centaurea cyanus (Punithalingam & Wheeler, 1965; Schneider, 1959). DISEASE: Formerly known as brown leaf spot or blight (Halsted, 1891; Cavara, 1892; Salmon, 1907; Moore, 1959) but now referred to as the black leaf spot of chrysanthemum (Hemmi & Nakamura 1927; Waddel & Weber, 1963) in order to distinguish the symptoms from those produced by Septoria obesa (CMI Descript. 139). The first visible leaf symptom is a small discrete necrotic spot. This gradually develops into a circular or elliptical spot seldom irregular, about 5-10 mm wide, at first dark brown, then turning black. Leaf spots of a purple to brown colour, with a distinct brown margin are not uncommon. The disease appears in susceptible chrysanthemum plants of all ages, first on the lower leaves and then gradually progressing upwards. This is a disfiguring disease and in a severe attack all leaves wither resulting in premature defoliation. GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Kenya, Malawi, Mauritius, Mozambique); Asia (China, Formosa, Japan, Pakistan, Philippines); Australasia (Australia, New Zealand); Europe (Austria, Azores, Bulgaria, Cyprus, Czechoslovakia, Denmark, France, Germany, Iceland, Italy, Norway, Portugal, Rumania, Spain, Yugoslavia, U.S.S.R.); North America (Canada, U.S.A.), Central America (Costa Rica, Cuba). (Literature; Herb. IMI). TRANSMISSION: Dimock & Allyn (24: 192) suggested the pathogen may survive the winter in the soil in infected debris from the previous season. The fungus may be disseminated by water splash or by mechanical means as with S. obesa.

Corrigendum - Apical chlorosis and leaf spot of Tagetes spp. caused by Pseudomonas tagetis Hellmers

1978 ◽  
Vol 29 (4) ◽  
pp. 831
Author(s):  
D Trimboli ◽  
PC Fahy ◽  
KF Baker
Keyword(s):  
Leaf Spot ◽  
Zinnia Elegans ◽  
Tagetes Erecta ◽  
Diverse Range ◽  
Biochemical Characteristics ◽  
Leaf Spots ◽  
Spray Inoculation

An undescribed apical chlorosis caused severe losses in seedlings of Tagetes erecta and T. patula types in Sydney, Brisbane and Melbourne in 1976. Bacterial leaf spots without chlorotic haloes invariably accompanied the disease. The same bacterium was isolated from leaf lesions and chlorotic tissue and produced leaf spots and chlorosis on marigold, zinnia and sunflower with spray inoculation. Leaf spots did not develop on T. signata. Apical chlorosis developed on a diverse range of plants following wound inoculation. The pathogen was shown to be seed-borne. The pathogen was identified as Pseudomonas tagetis, cultural and biochemical characteristics described, and a neotype culture proposed. An exotoxin was produced in vitro which caused apical chlorosis in Zinnia elegans and T. patula.

scholarly journals Potential biocontrol of Echinochloa crus-galli (Barnyard grass) by Curvularia lunata LD2 as a Mycoherbicide

2019 ◽  
Vol 8 (3S2) ◽  
pp. 281-286
Keyword(s):  
Leaf Spot ◽  
Fungal Pathogens ◽  
Severe Infection ◽  
Control Agent ◽  
Leaf Spot Disease ◽  
Curvularia Lunata ◽  
Barnyard Grass ◽  
Tropical Regions ◽  
Noxious Weed

Echinochloa crus-galli (commonly known as barnyard grass) is a noxious weed causing loss of several economically important field crops in tropical regions . An intensive work on the screening of the bio control agents was accomplished through in vitro epidemic study to control weed populations. The foliar disease symptoms on infected weed plant caused by fungal pathogens represented as round to irregular maroon spots with dark borders and the epidemic was indent fields as leaf spot disease. The pathogen allied with the infection of barnyard grass was isolated from infectious propagules by inoculation of leaf bites on a potato dextrose agar (PDA). The caused agent of leaf spot was confirmed as barnyard grass by Koch’s postulates. The mycoherbicide ability of Curvularia lunata to control barnyard grass has been examined through visual (standard are diagram) and statistical methods. The results revealed that the pathogen causes significantly severe infection on host weed and destructs the weed population by leaf spot diseases. The findings of the research suggested that the isolate barnyard grass is highly virulent and host specific and recommended for further studies as a promising bio- control agent against barnyard weed.

Cercospora cruenta. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
J. L. Mulder
Keyword(s):  
Geographical Distribution ◽  
Vigna Unguiculata ◽  
Leaf Spot ◽  
Vigna Radiata ◽  
Mucuna Pruriens ◽  
Phaseolus Aureus ◽  
Vigna Sinensis ◽  
Leaf Spots ◽  
Brown Leaf ◽  
Stem Lesions

Abstract A description is provided for Cercospora cruenta[Mycosphaerella cruenta]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Vigna sinensis[Vigna unguiculata] and V. unguiculata; also on Calopogonium, Lablab niger, Phaseolus spp. and Stizolobium deeringianum[Mucuna pruriens]. DISEASE: Leaf spot of cowpea. On Phaseolus aureus[Vigna radiata] the leaf spots are more or less circular, purplish-red and mostly with light grey centres, usually 3-4 mm diam. ; large, irregular necrotic patches, limited by the veins, are formed, pods are destroyed, purplish stem lesions are up to 4 cm long (4, 75). On Vigna sinensis[Vigna unguiculata] the reddish-brown leaf spots (becoming necrotic) can be 1 cm diam., outline irregular, there may be coalescence of the spots and leaflets wither (14, 280; 42, 168). GEOGRAPHICAL DISTRIBUTION: Widespread in warmer regions. TRANSMISSION: No studies reported.

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